If you’re waiting until the last minute to sign up for coverage under President Barack Obama’s health care law, a little extra patience might come in handy.

HealthCare.gov, the online portal to taxpayer-subsidized health insurance, runs slowly when compared with major private health insurer websites. That’s according to an analysis for The Associated Press by Compuware, a Detroit company that measures website performance.

The tests found that response time for HealthCare.gov averaged nearly nine seconds nationally over the seven-day period that ended Tuesday. Generally, response time for leading private health insurance websites averages just under five seconds. Based on that real-world comparison, Compuware says the speed of HealthCare.gov is “unacceptable.”

On the positive side, HealthCare.gov was available more than 98 percent of the time, about average for the industry.

Compuware defines “response time” as the time it takes a first-time user to load the home page for a given website. The company’s tests did not attempt to go through the entire process of applying for health insurance, which involves submitting personal and income details, getting the information verified by government agencies, and finally selecting a plan.

This week is crunch time for the federal health care website. Open enrollment ends Monday. After March 31 most consumers will have to wait until Nov. 15 for their next chance to sign up and receive tax credits to help pay their premiums.

The administration said late Tuesday that people who’ve started applying for health insurance but aren’t able to finish before the March 31 deadline will get extra time. It was unclear how long the extension would last.

“As a taxpayer I’d be thinking, did we get our money’s worth?” said Michael Smith, Compuware’s vice president for engineering. “I’d be very concerned coming up against a deadline. … My main concern is how would this site stand up under load?”

HealthCare.gov had more than 1 million visits Monday and was holding up well, he said, unlike what happened in October when the site was down most of the time.

If the site starts seeing very high demand, Albright said technicians have built an advanced queuing system that creates a “waiting room” where people can hold for a short period of time. Consumers can also leave an email address and be invited back when the system is ready.

As for response times, Albright said the government’s own measurements show average times have dropped to less than half a second.

Smith said the government might be getting those blazingly fast times by testing its system from data center computers. Compuware uses software installed on laptops and desktops of actual consumers to perform its tests. Dial-up connections were filtered out of the HealthCare.gov analysis.

“The sub-one-second time is not what real users are experiencing when they use the site,” he said.

Getting covered using the website is still nowhere near as simple as shopping elsewhere online. Consumers make an average of six visits to HealthCare.gov, spending 20 minutes to 30 minutes per visit, an administration official told reporters on a recent teleconference call.

The White House is scrambling to get 6 million people signed up in the new health insurance markets by March 31. Presidential spokesman Jay Carney had told reporters last week that the administration wanted to make sure “that people who are already in line can finish their enrollment.” He pointed to what happened in December when consumers got an extra day to enroll for coverage effective Jan. 1.

Officials didn’t call that an extension, or even a grace period. They compared it to the Election Day practice of allowing people to vote if they are in line when the polls close.